Intercomparison of micro-liquid flow standard system in APMP

Abstract

A pilot study was conducted to compare the microflow rate from 2 to 200 g/h in the APMP TCI project (TCFF_01_TCI2019). A syringe pump (Chemyx Nexus 3000) and Coriolis flowmeter (Bronkhorst M12) were used as the transfer standards. The comparisons were coordinated in the KRISS institute, which was also responsible for the pilot study. The volumetric flow rate was measured using a syringe pump and the measured flow rates were 33, 100, 333, 500, and 1000 μL/min and the institutes that participated in the international comparison of micro-liquid volumetric flow rates were KRISS, NMC A*STAR, and CMS, all of which used water as the working fluid. To measure the mass flow rate, a Coriolis flow meter was used; the flow rates were 2, 6, 20, 60, and 200 g/h and the institutes that participated in this international comparison of micro-liquid mass flow rates were KRISS, NMC A*STAR, CMS, NMIJ, and NIMT. All of the participating institutes used water as the working fluid, except for the NMIJ, which used light oil. The En values for the syringe pumps and mass flow meters were calculated based on reference values and were less than 1 for all the flow rates determined by the participating institutes. Therefore, the international equivalence of the microliquid flow standard system of the participating APMP institutions was confirmed.